西南旱地油菜间作紫云英和秸秆覆盖的生产效应

我国西南地区旱地的农田生态环境脆弱,绿肥应用匮乏,季节性干旱是限制油菜生产的关键因素。本研究在西南地区旱地引入冬季绿肥作物紫云英与油菜间作,并结合秸秆覆盖,探讨其对油菜光合特征、农艺性状、生物量、根系形态、油菜品质及产量的影响。结果表明,间作紫云英和秸秆覆盖改善了油菜的根颈粗、叶片数、有效分枝数和单株角果数等农艺性状,提高了油菜根系总根长、总根体积、总根表面积和平均根系直径等根系形态及蕾薹期和开花期的根、茎、叶生物量;还提高了油菜苗期光合作用强度,间作和秸秆覆盖处理的水分利用效率比油菜单作分别提高了31.12%和39.89%;但对油菜品质的影响较小。间作、秸秆覆盖和秸秆覆盖下间作的油菜群体产量分别比单作提高10.30%、13.20%和40.16%。在西南地区旱地,间作紫云英是提高油菜产量的可行途径,而且结合秸秆覆盖的生产效益更明显。

Influences of Rape Intercropping with Chinese Milk Vetch and Straw Mulching on Productive Benefits in Dryland of Southwest China

In dryland of the southwest of China, the eco-environment of farmland is extremely fragile, and the application of green manure is not enough. The seasonal drought is a key factor limiting the rape production. In order to improve rape yield and explore the application method of green manure, we compared the effects of intercropping and straw mulching on photosynthetic characteristics, agronomic traits, biomass, root morphology, rapeseed quality and yield. Intercropping Chinese milk vetch and straw mulching substantially improved the agronomic traits (diameter of root crown, leaf number, effective branch number and number of pods per plant), the root morphology (total root length, total root volume, total root surfarea and average root diameter), and the biomass of root, stem and leaf at stem elongation, flowering and podding stages of rape. At the same time, it also increased the photosynthetic rate at seeding stage. Water use efficiency in intercropping treatment and straw mulching treatment was increased by 31.12% and 39.89% as compared with rape monoculture. In addition, treatments of intercropping, straw mulching and intercropping with straw mulching significantly increased rape yield by 10.30%, 13.20%, and 40.16% as compared with rape monoculture. Our findings revealed that intercropping Chinese milk vetch and straw mulching are helpful to improve the agronomic trait, biomass and root morphology, resulting in yield increase in rape.